Electrohydraulic extrusion of spherical bronze (CuSn6) micro samples

Conventional material testing strategies are time and cost intensive. In this paper, a new method for contactless high-speed testing of spherical micro samples by an electrohydraulic punch is introduced. The punch transfers the punching force incrementally to extrude the samples stepwise in dies with high aspect ratios. The sample’s material behavior is characterized by analyzing the deformation behavior between the extrusion steps and at different forming stages

Removal of SO2 from the marine boundary layer over the Atlantic Ocean : a case study on the kinetics of the S(IV)oxidation on marine aerosols

Measurements of SO2 and NSS-SO42- were made over the Atlantic Ocean on board the RV Polarstern from October 9 to November 2, 1996, as part of the ALBATROSS campaign. The measurements were performed between 66.7 degrees N and 37.8 degrees S with a mean longitude of approximately 30 degrees W. The most frequent background values for SO2 were found to be 13 parts per trillion by volume (pptv) (0.54 mnol m(-3) at standard ambient temperature and pressure (SATP)) in the Southern Hemisphere, and 15 pptv (0.62 nmol m(-3) SATP) in the Northern Hemisphere. The mean values for total NSS-SO42- in particles with a d > 0.2 mu m were (5.99 +/- 2.93) nmol m(-3) (SATP) in the Southern Hemisphere, and (8.93 +/- 5.29) nmol m(-3) (SATP) in the Northern Hemisphere. An analysis of the size-fractionated aerosol samples (d > 1 mu m and 0.2 mu m 1 mu m. The main fraction of this NSS-SO42-. is most likely produced by the oxidation of dissolved SO2 via heterogeneous reactions occurring in the aqueous phase of coarse mode marine aerosols. A case study on the kinetics of this oxidation pathway was conducted during ALBATROSS. October 12, 1996, the ship sailed in the plume of a volcano on Iceland during its eruption from September 30 to October 13, 1996, as indicated by trajectory analysis and by the measurements of NSS-SO42- SO2, CO, and Hg, An empirical physicochemical approach considering the atmosphere as a natural flow reactor is used for the presented case study. The determined pseudo-first-order reaction rate constant for;the oxidation of SO, on marine aerosols is 3.31 x 10(-4) s(-1) at 25 degrees C. Assuming that the occurrence of coarse mode marine aerosols is the rate-limiting variable of the reaction, the second-order reaction rate constant is found to be 1.32 x 10(-6) cm(3) s(-1) particle(-1) at 25 degrees C. These values are in good agreement with results of previous field experiments as well as with the results of model studies

Numerical and experimental design of graded cellular sandwich cores3 for multi-functional aerospace applications

The present contribution is concerned with a combined experimental and numerical design of graded cellular materials for multifunctional aerospace application performed in the context of an integrated research project funded by the European Commission. The primary objective is an exploration of the potential of functionally graded materials as sandwich cores for multifunctional application. With particulate advanced pore morphology (APM) foams and hollow spheres assemblies, two different types of particle-based cellular base materials are considered. Based on these constituent materials, functionally graded sandwich cores are designed in a combined numerical and experimental approach. Their properties and their performance in the desired application are investigated and optimized. The performance of the optimized material is compared to the performance of a non-graded sandwich core in the numerical simulation of a bird strike experiment